Comments:

2010-03-24 22:58:51 Today I was waiting at a bus stop and I found a pile of these weird insects on top of something. Some of them had a red rear end and the rest was black. They looked like slightly large ants and at first I thought they looked like worms or something until I realized that another one of the bugs were attached to the rear end of the other bug. Anyone have a clue what these could have been? —hankim

2010-03-24 23:12:08 I have always wondered what those are and why they are stuck to each other, they seem to be very numerous this time of year. —DagonJones

2010-03-25 10:06:51 Koelreuteria paniculata is a host, as are maples. They aren't particularly harmful, but the populations can get locally so large that they are a nuisance. They do seem to be in a permanent state of copulation. —DonShor